School buses have commonly included illuminated stop signs which extend from the side of the bus to notify traffic to stop allowing children to safely cross the road. Exemplary of such a stop sign is U.S. Pat. No. 5,357,239, issued Oct. 18, 1994, and assigned to the assignee of the subject invention. The stop sign includes the word STOP printed in reflective material and two flashing lights connected in the upper and lower portion thereof. The sign is pivoted to extend outwardly from the bus and flash when children are being loaded or unloaded from the school bus.
Other related STOP signs are illustrated in U.S. Pat. No. 4,559,518, issued Dec. 17, 1985 in the name Latta, Jr., and U.S. Pat. No. 5,036,307, issued Jul. 30, 1991 in the name of Reavell et al. Both of these patents disclose a pivotal stop sign which extends from the side of the bus and which includes the word STOP thereon with two lights above and below the word.
However, in all of the designs, the use of flashing lights may blur the word STOP and therefore may not positively instruct drivers to stop. Furthermore, weather conditions may deteriorate the externally located power conductors.
Other illuminated signs with indicia thereon have used neon lights, LEDs, fluorescent bulbs, etc. Such lights illuminate a portion of the sign to display indicia, such as words or symbols. Exemplary thereof is U.S. Pat. No. 4,891,896, issued Jan. 9, 1990 in the name of Boren which discloses a simulated neon sign wherein a housing includes raised letters. A pigmented translucent coating is applied to the letters so that light from the interior can pass through the indicia. To simulate the halo effect of a neon light, additional pigmented coating is applied to the nonprojecting region. Fluorescent bulbs are utilized to illuminate the display.
U.S. Pat. No. 5,299,109, issued Mar. 29, 1994 in the name of Grondal discloses an LED exit light fixture which includes a frame and cover therefore that has a translucent and nontranslucent portion to define the word EXIT. The light emitting diodes are positioned directly beneath the nontranslucent portions of the cover and adjacent the translucent portions in order to provide a uniform illumination of the word. Another type of LED exit lamp is illustrated in U.S. Pat. No. 5,303,124, issued Apr. 12, 1994 in the name of Wrobel.
U.S. Pat. No. 5,345,705, issued Sep. 13, 1994 in the name of Lawrence discloses a three-dimensional, contoured surface of a sign, which may include a light emitting diode therein to enhance the sign to a viewer.
An LED stop sign has been proposed wherein a hexagonal-shaped board includes a plurality of apertures therein, and LEDs are connected on a circuit board to extend through the apertures. The LEDs define the word STOP. However, this design is not practical in the bus environment or other external uses where variable weather conditions exist.
There is a need to more clearly indicate to passing drivers the instructions to stop when the sign is displayed and children are being unloaded or loaded from the school bus, and to provide a sign which can withstand variable weather conditions.